Powder coating compositions are extremely desirable for use in painting substrates in that they are essentially free of organic solvents conventionally utilized in liquid paint systems. Thus, they give off little, if any, volatile material to the environment when heat cured.
Powder coating materials comprising (1) a copolymer of a glycidyl acrylate and other monofunctional olefinically unsaturated monomers (2) an anhydride crosslinking agent and (3) a polymeric flow control agent were heretofore described in our U.S. Pat. No. 3,781,379. Powder coating materials comprising (1) a copolymer of a hydroxy acrylate and other monofunctional olefinically unsaturated monomers, (2) an anhydride crosslinking agent and (3) a polymeric flow control agent were heretofore described in copending U.S. Pat. application Ser. No. 407,128 filed Oct. 17, 1973 by Santokh S. Labana, a coinventor herein, and Yun F. Chang.